Regions
South Coast Inland.
Forecast new snow and wind on Tuesday night will add to an ongoing storm slab problem with increased reactivity expected in the alpine.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
WEDNESDAY NIGHT: 10-15cm of new snow / Strong southwesterly ridgetop winds / Freezing level around 1000m.THURSDAY: Mostly cloudy with flurries; 3-5cm / Moderate to strong southwesterly ridgetop winds / Freezing level dropping to 500m.FRIDAY: Mostly cloudy with flurries; 3-5cm / Light southerly ridgetop winds / Freezing level around 500m.SATURDAY: 5-10 cm of new snow / Light to moderate southerly ridgetop winds / Freezing level around 500m.
Avalanche Summary
No new avalanches have been reported, but that may speak more to a lack of observations rather than actual conditions. Additional snow and wind Wednesday night will continue to create touchy storm slabs reactive to human triggers, especially in the alpine.
Snowpack Summary
20 cm of new snow on Wednesday morning brings recent storm totals to 60-80cm. Moderate southerly winds continue to redistribute the new snow. Last weekend's strong to extreme southeasterly ridgetop winds likely created dense storm slabs lurking in lee and cross-loaded features at treeline and above.50-120cm below the surface you'll likely find a few crusts that were buried during the first few weeks of January. Due to limited observations, not much is known about the current reactivity of these layers.The lower snowpack includes the mid-December crust layer. I'd expect an improving bond at this interface; however, the load of the new snow may tip the balance and reactivate this layer in isolated terrain - particularly in the north of the region where it's shown prolonged reactivity in snowpack tests.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.